Improvement in artificial limbs



UNITED STATES PATENT OFFICE.

ABNER MCOMBER, OF SOHENFOTADY, NEW YORK.

IMPROVEMENT IN ARTIFICIAL LIMBS.

Specification forming part of Letters Patent No. 56,243, dated July l0, 1866.

To all 'whom 'it may concern:

Be it known that I, ABNER MGOMBER, of Schenectady, in the county of Schenectady and State of New York,`have invented a new and useful Improvement in Articial Limbs; and l do hereby declare that the following is a full, clear, and exact description thereof,

which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is an elevation of a vertical section of a foot and of a portion of a leg below the knee, showing also the straps by which the same are attached to the thigh or part above the knee. Fig. 2 nis a sectional view of a kneejoint. Fig. 3 is a side View of such joint. Fig. 4; is a sectional view of an ankle-joint. Fig. 5 is a side view of an ankle-joint. Fig. 6 is a sectional view of an artificial limb embracing the foot, (except the part that'represents the toes,) the lower part of the leg from the foot to the knee, and a portion of the leg above the knee. Fig. 7 is a plan, and Fig. 8 a longitudt nal section, of the frame O, that holds the lower end of the cord U.

Similar letters of reference indicate like parts.

The object of this invention is to improve the construction of artiiicial limbs, both for amputations below and above the knee.

Theinvention embraces, among other things, an improved elastic connection between that part of the foot which represents the toe and the rest of the foot; also, an improved connection between the foot and the leg at the place of the ankle; also, an improved method of making the knee-joint so that compensation is provided for the wear of the joint, and the patient can himself tighten it when it w'ears loose; also, in providing means for Ventilating the cases of the limbs also, in covering the foot with felt or other soft material, so as to preserve the stocking; also, in fastening the cord which connects the leg to the foot to a yielding bearing in a removable frame inserted in thebottom of the foot.

I have here shown my invention applied and carried ont both where amputation has been made of the leg and also of the femur or thigh, in the rst instance the artiicial limb being provided with straps to secure it to the thigh as shown in Fig. 1.

rIhe letter A designates the case which represents the leg, and D the foot. The case A is hollow, and is perforated with holes N, to admit air for ventilation below the stump of the natural leg, which is received into the open top ofthe case. The case A is attached to the stump by means of elastic straps B, three or more, starting from the sides and back of the case, and made of such a length as to reach above the knee, where they are connected to a common strap, C, which crosses them at right angles and which is secured horizon tally around the thigh. The ends of the straps B have buckles or other devices, whereby they A can be connected to other straps descending from the hip, if desired.

VThe foot D is covered with sheepskin E,

`ing the stocking from wearing out by coming between it and the hard surface of the foot.

F is the part of the foot which represents the toes. Instead of being rigidly connected to the foot, it is here connected by a joint, H, which is so made as to allow the toe part to be bent upward when the weight of the leg colnes on it in the act of walking, the said toe part being restored to its normal position when the weight is taken o by means of elastic cylindrical pieces L, one of which is seen in Fig. 6. The ends of said cylindrical pieces rest in sockets, both in the toe part F and in the body of the foot, such sockets being above the point m of the joint H. Vhen the part F is bent up in the act of walking, the elastic pieces L are compressed, and when the weight of the leg is taken of the part F the elasticity of the pieces L restores it to its normal position. In lit-ting and adjusting these parts the lower edge of the toe part Fis brought close to the lower edge of the foot, while their upper edges are left a little ways apart, so as to allow the part F to vibrate on its hinge. The space so left is covered over by a strip, u, of leather or other flexible material.

A cavity, Gr, is made in the sole of the foot to receive a frame, d, composed of two side pieces connected by cross-pieces i z' and f. The cross-piece f goes through the end of a vibrating bar, c, placed within frame d, said bar being free to vibrate on the crosspiece as its center of motion. The free end of the bar extends beyond the frame, and is perforated to receive the lower end of the cord U, which passes thence up through the foot into the leg, in which it is secured by means of a crosspiece, S.

The bar face c, and consequently the cord U, are kept down to their lowest position by means of a spring composed, in this example, of an endless elastic band, g, placed within frame d and passed around the most forward one of the cross-pieces i, thence beneath the other cross-piece, thence through a slot, h, in the bar e, above which it is held by a cross-piece, 7c, over which it is passed, the ends of said cross-piece being made to rest on the edges of the slot, and so kept above the bar.l

The action of this part of the apparatus is as follows: AWhen the foot .D is raised from the ground in the act of walking, it swings around the leg so as to bring the weight on the cord U, whichv consequently draws the bar e upward against the elastic band g, the height of the frame allowing the bar and the loose cross-piece 7a to be moved upward a little distance. When the cord U is relieved of the weight of the foot, the elasticityof the band immediately begins to restore the foot to its normal position with respect to the leg A by drawing the bar e and the end of the cord U to their lowest position, thereby enabling the foot the more readily and gracefully to resume a horizontal position on the ground.

The heel of the foot isconnected to the leg by a cord, V, representing in some respects thek tendon Achilles. It is secured in any suitable way to the heel, and its upper end is carried upward within the leg and fastened adjustably or otherwise, as desired, to the cross-bar S.

The thigh or femur 1s represented by the 'hollow case M, whose top is formed to receive the stump of the patient, and whose bottom is formed to fit in the hollow top ofthe leg.

A curtain, p, extending from the hinder part of the case M, reaches to the edge of the leg, but is not fastened thereto. This curtain hides the opening made behind the place of the knee when the knee isflexed.

The thigh and leg are connected by a joint, R, the hinge of which goes through metallic plates extending up ward from the sides of the leg and through the solid lower end of case M. The hinge is composed of a headed bolt, which does not go through the joint, but whose inner end is hollow and has a screw-thread cut in it to receive a screw, X, from without, as seen in Figs. 2, 3, and 4. This hinge works in bushings Y, of very hard wood-such, for instance, as lignum-vit-made in two equal parts and of a length about equal to the hinge.

Beneath the bushings Y is a triangular cavity, which receives a wedge, Z, that is drawn inward by a screw-bolt, c, which works through a nut, a, that extends from one side of the wedge into a cavity, b, whose length is such as to allow the nut to traverse a sufficient distance for the proper action ofthe wedge against the bushing.

The object of the wedge is to prevent the joint of the hinge from becoming loose by wearing, and it prevents such a result by being drawn inwardly by turning the bolt c, whose head is slotted to receive a screw-driver, and whose screw-thread is confined to that part of it which is within the cavity b.

When the bolt c is turned the nut a is drawn forward, bringing with it the wedge Z, which,-

connection of the leg and foot is made as4 shown in Fig. 6, where the bottom of the leg is `cut off square and is received in a square recess formed in the top of the foot, the joint itself being made by rounding the lower end of the block q, which contains the hinge, and letting it rest and play in a socket, W', formed in the top of the foot.

By placing the hinge of the ankle in a block, q, whose lower end makes a joint with the foot, it is evident that the joint and hinge will remain always in the same relative positions.

In order to prevent the leg from being extended or projected too far forward in the act of walking', it is connected to the thigh by a cord, Q, which is fastened around the crossbar S at the front part of the leg, and is thence carried up in an inclined directionto the bottom of the thigh, which it enters back of a vertical line passing through the kneejoint hinge R, and is secured in the bottom of the chamber P, where itcan be easily reached to be adjusted.

It will be observed that the cord Q is thus bent nearly at a right angle below and back of said hinge, and that it has theeffect of preventing theleg from being put forward beyond the line of the thigh. Y

The chamber P in the lower part of the thigh is liable to become littered with dust and foreign matter, which come from the natural wear and attrition of the parts and of the garments that cover the stump. To prevent such matters from reaching the bottom of the chamber, I interpose a false bottom, O, having an opening in its center for inserting cord Q, said false bottom being kept from displacen ment by narrowing the chamber at r.

The joints shown in the several igures are not drawn to a nice adjustment, as they are required to be made for use, the object being,

as in the case of the joint W in Figs. 4, 5, and

6, to illustrate the construction the more distinctly by slightly separating the parts of the joint from each other.

Having thus described my invention, I claim as neur and desire to secure by Letters Patent- 1. Giving a yielding bearing to the lower end of cord U by means of the elastic band g and vibrating,` bar, substantially as above set forth.

2. Placing the elastic band g and vibrating bar e in a movable frame, d, and also fitting said frame in a cavity, G, in the bottom of the foot, substantially as shown.

3. Bushing the hinges of artificial limbs with divided bushings Y, of lignum-vitae or other hard wood, and taking up the Wear of the bushing by means of a Wedge, Z, operated substantially as above described.

ABNER MGOMBER.

Witnesses:

JOHN BRADT, JOSEPH HoRsFALL. 

